Blindstitch sewing machine



Filed Dec. 1924 4 Sheets-Sheet 1 Mmuumbw ATT Jul 13, 1926.

Filed Dec. 1 24 4 Sheets-Sheet 2 & INVENTOR M 0,, MM

WITNESSES July 13,1926. m 1,592,446

C. A.- DEARBORN BLINDSTITCH SEWING MACHINE Filed Dec. 25, 1924 4 Sheets-Sheet ,1 I lmlllv WITNESSES INVENTOR M shi -MM C. A. DEARBORN BLINDSTITCH SEWING. MACHINE July 13 1926.

Filed Dec. 23, 1924 4 Sheets-Sheet 4 taken on the line 6-6 of Fig. 1;

Patented July 13, 1926.

UNITED STATES 1,592,446 PATENT OFFICE.

CHARLES A. DEABBORN, 01'' NEW YORK, N. Y.

nnmns'rrron snwme maonnin.

I Application filed December 23, 1924. Serial No. 757,653.

"The present invention relates to blind stitch sewing machines of the general type illustrated'in my prior Patents No. 639,669, dated December 19th, 1899, and No. 814,025,

dated March 6th, 1906.

v The object of the present invention is to improve and modify this type of sewing machine to adapt it more especially for felling piped edges of seams. To this end the loop 1 or movement has been modified to carry a second thread and produce in combination with the needle thread a double chain stitch. The looper operating means have been improved to cause the looper to move forward 5 1y above the needle and presser foot on one side of the line of stitches, and backwardly below the needle on the same side of the line of stitches, and to turn 90 at the ends of its forward and backward strokes. The

1 presser foot has in the past usually been a single rigidly supported member against .which the work is pressed by a yielding work 'support. In' the new machine the presser foot is divided, the main part at the 5 left of the ridge forming rib above the work support being fixed, while the auxiliary part at the right of the ridge forming rib is mounted upon a spring'supported arm to yield laterally away from the line of 9 stitching under the strain of an extra heavy part of the work such as is encountered with heavy cross seams.

In order that the invention may be fully understood it will first be described with 5 reference to the accompanying drawings and afterwards pointed out more particularly in the annexed claims:

In said drawings:

Fig. 1 is a side elevation of the improved 3 blind stitch felling machine;

Fig. 2 is a plan view of the same with the sewing machine arm,the needle shaft, and other parts broken away for the sake of clearness;

5 Fig. 3 is a detail front elevation of the stitch forming mechanism, showing also the work supporting mechanism in section;

Fig. 3" is a detail side elevationof parts shown in Fig. 3; 1

Fig. 4 is a detail view similar to Fig. 3,.

showing the needle in its retracted position; Fig. 5 is a vertical longitudinal sectional view taken on the line 55 of Fig. 3;

Fig. 6 is a detail horizontal sectional view Fig. 7 is a detail transverse sectional view taken on the line 77 of Fig. 1;

Fig. 8 is a detail side elevation of the looper movement showing the looper nearing its rearmost position;

Fig. 9 is a detail plan view of the looper and needle in the same position as Fig. 8;

Fig. 10 is a plan view of the looper movement showing the looper withdrawn to its extreme rear position;

Fig. 11 is a detail side view of the needle and looper in the position illustrated in Fig. 10;

Fig. 12 is a view similar to Fig. 8 showing the looper starting'on its forward motion;

Fig. 13 is a detail plan view of the needle and looper in the position of Fig. 12;

Fi 14 is a plan View similar to'Fig. 10 showing the looper in its extreme forward position; and

Fig. 15 is a detail view illustrating the relation of the needle and looper corresponding withthe position shown in Fig. 14. I

j 1 is the main frame of a sewing machine of the type set, forth in my above named patents and 2 is the sewing machine arm projecting forwardly from the main bearlng 3 to a point above and adjacent to a work support presently to be referred to. The frame 1 has an upwardly presented rigid arm .5 in which is rigidly mounted the horizontal bolt 6 upon which is journalled a rocking frame 7, which projects rearwardly and forms a U-shaped yoke carrying the ridge forming disk 10 journalled il'l'lt at 11 and the independently yielding working supporting plates 12 pivoted at 13 uponarms 14 journalled at 15 and controlled by springs 16. c5

The U-shaped frame 7 has a downwardly projecting arm connected at 21 by a strong contractile spring 22 attached at its inner end to a flange 23 of the machine frame 1.

An adjusting screw 25 is threaded in lugs 26 of the machine frame and engages at its forward end with the arm 20 and is provided at its rear'end with a milled hand operated head 27 by which the screw, can 1 be adjusted. The head 27 has a bevelled face- 28 marked ofi in a suitable scale to indicate at a glance the adjusted position of the screw 25. Adjacent to the head 27 is a grooved cylindrical portion 29 with which engages a spring detent mounted upon a pin 31 of the machine frame and serving to hold the adjusting screw 25 against accidental displacement. A second screw 33 is adjustably mounted in the lug 26 in the path of the arm 20 to limit the movement of the arm in one direction under the action of the spring 22.

35 is the main fixed portion of the presser foot secured to the lower end of a plate 36 which is adjustably mounted on a vertical face of the machine arm 2 by means of machine screws 37. This fixed portion of the presser foot is mounted above the work sup-V, port to the left of the ridge forming rib and carries additional elements hereinafter referred to.

66 is a shoe formed on the lower end of plate 67 secured to a vertical face of machine arm 2'by screws 68. The shoe 66 is fixed in the horizontal plane of the presser foot alongside of the reciprocating feed dog- 70,

- hereinafter referred to, and serves to confine presser foot member 40 a spring ten of the the work downwardly adjacent-to the feed. 40 is the auxiliary laterally adjustable portion of the presser foot consisting of a short forwardly presented blade mounted upon the lower end of a curved lever 41 piv oted to the sewing machine arm by means of a screw 42 and havin an arm 43 projecting to the left above a limiting stop 44, which confines the extent of movement of the auxiliary presser foot member away from the fixed member. A contractile spring 45 engages the arm 43 and connects with an arm 46 upon the machine frame for givin the ency to move inwardly toward the vertical plane of the ridge forming disc 10. This spring motion of the auxiliary presser foot is limited by a conical adjusting screw 50 threaded in the machine arm and engaging arm 43 of lever 41. From this structure it will be observed that this auxiliary portion 40 of the presser foot is free to yield outwardly" against the action of spring 45 up to the limit of stop 44. Laterally yielding member 40 is presented directly in front of-feed dog 70 and above the right-hand work supportmg dplate 12. Member 40 cooperates with fixe shoe 66 in resisting upward pressure work passing over the work supportr is the curved needle carried by the arm 61 adjustably mounted upon the needle rock shaft 62 driven by the rock arm 63, the universal joint link 64 and eccentric on the main drive shaft 65 in the same manner as previously employed in this type of machine. The needle reciprocates in guide grooves formed in the concave upper faces of the main and auxiliary portions of the presser foot 35 and 40.

is the two part reciprocating upper feed secured by screws 71 to the forward projection of the oscillating rerprocating Laeaeee feed bar 75 which is driven at its rear end by eccentric connection 76 with the main shaft of the machine and supported between its ends by a headed guide pin 77 projecting laterally from a lug of the machine arm and adjustably secured'therein by set screw 78. This pin 77 passes through a slot in the feed bar 75 and confines it to its vertical plane of operation. The feed bar 75 has a universal oint 80 with a link 81 which in turn has a universal joint 82 with a rock arm 83 adjustably mounted upon the needle rock shaft 62 by means of set screw 84.

is the looper proper adjustably mounted in the forward end of a cylindrical looper bar 91 which is secured at its rear end to a yoke 92trunnioned upon an eccentric lug 93 of a bearing sleeve 94, which is journalled upon an angularly set crank pin 95 of the crank disk 96 carried by the main shaft 65 of the machine. This angularly set crank with universal joint connection with the looper rod is similar to that shown in my above named patents and forms part of the present invention excepting only as an essential part of the mechanism for operating the ooper in the manner hereinafter described.

The looper bar 91 passes freely through aligned bearing sleeves 100 of a floating bearing frame 101 which is formed at its forward end with a bearing yoke 102 freely pivoted at 103 upon the lower end of a vertical pivot pin 105, which turns freel in bearing 0 ening 106 formed eccentrical y in the cylin rical bearing block 107 which is mounted adjustably in the split socket 108 of the sewing machine arm. This bearing block 107 is formed with a squared upper end by which it can be turned in the split socket of the machine frame and secured in the desired adjusted position by the set screw 110. By adjusting the block 107 the vertical pivot pin can be shifted laterally and forwardly and backwardly for accurately positioning the point of the looper to cause it to properly cooperate with the needle. The pivot pin 105 is confined in the bearing block 107 by means of the headed set screw 109 threaded in the upper end of pin 105 and engaging the upper end of bearing block 107.

One of the important accomplishments in modifying this type of blind stitch sewing machines to adapt it specially for felling heavy seams is the reduction in the throw of the looper from the lower plane of its backward stroke to the upper plane of its forward stroke. The distance between these two planes of movement of the looper is barely more than the thickness of the needle. This. slight vertical throw between the two planes of movement of the looper is accomplished by mounting the pivot pin 105 of floating bearing frame 101 as far forward in the machine frame as is possible.. It will be noted that the pivot 103 of said floating the needle is withdrawn from the work,.t he' bearing frame 101 is just back of the transverse path of the needle. This looper movement is important also because it places the looper in its forward position above the path of the needle with the eye of the looper extending horizontally above the fixed portion of the presser foot conveniently for threading the looper.

'of the looper 90.

130 is a cloth engaging member pivoted in the slotted forward end of presser foot 35 and engaged by a spring 131 for holdin its cloth engaging downwardly presente end 130 alongside of the ridge forming disc 10.

When the work is placed in the machine, the work support is depressed usually by a foot pedal (not shown) connected with U- shaped frame 7 and the work inserted be-. tween the supporting plates 12 and the two part presser foot, the heavy or hemmed portion of the work being presented at the right of the ridge forming disk beneath the laterally' yielding foot member 40. The edge of the seam, which is commonly piped, is presented over the ridgevformingdisk 10 and the work at the left is pressed downwardly by the spring pressed plate or do 130 to confine the work as closely as possi le upon the disk 10 to thereby maintain theline of stitches closely beneath the piped edge of the seam. The upstanding rib 120 diverts the piped edge "of the seam slightly toward the disk 10 to hold it out of the way of the top feed member which engages the work parallel with the longitudinal groove 125.

The. threading of the needle and looper is indicated in the drawings and the cooperation of the needle and looper in forming a double thread. chain stitch will be-fully understood from Figs. 8 to 15 of the drawings. Starting the looper and needle in the position shown in Figs. 10 and 11 with the needle penetrating the work and the looper in its extreme rearward position, the looper moves forward in its upper plane abovethe needle, taking the loop from the "needle as feed dog feeding the work one stroke over the work support. In completing the forward movement of the looper and the retraction of the needle, the looper vpasses through the position shown in Fig. 12 into the position shown in Fig. 14. The final movement of the looper is from the position shown in Fig. 14 to that shown in Fig. '8,

which movement, withdraws the looper rear wardly in its lower plane beneath the path of the needle, while the needle again penetrates the work above'the disk 10 and takes the upstanding loop from the point of the looper. This cycle of movements is repeated for each stitch. All of the movements of the looper are performed on one side of the line of stitching.that is to the left of the vertical plane of the ridge forming disk looking at the front of the machine. The looper movement of my present invention is clearly distinguishable in this characteristicfrom the machine of my above named Pat- .ent No. 639,669, in which the looper oscillated backand forth from one side to the other of the line of stitching.

The inclined crank pin yoked to the end of the looper rod causes the looper to oscillate back'and forth 90 as it reciprocates across the path of the needle. This quarter turn of the looper is made for several reasons. In the first place, it turns so as to present the eye of the looper horizontally above the presser foot in convenient position for threading the looper. It would be practically impossible to thread the looper .unless it were turned in this way. This needle as the needle takes the loop from the looper. In this latter position the looper thread is held firmly and given substantial lateral support in the path of the needle by l the walls of the looper eye because of the I thickness of metal of the looper at the eye.

,The improved work handling mechanism '.means, the combination of a reciprocating needle, and a looper operating above the work support and presser foot and cooperating with said needle, with looper operat-' ing means adapted to cause said looper to move forwardly above the needle on one side of the line of stitches and ba'ckwardly below the needle on the same side of the line. of stitches, and to turn '90? at the ends of its forward and backward strokes.

support, a presser foot and work feeding means, the combination of a. reciprocating needle, and a looper formed with a thread carrying eye cooperating with said needle, with looper operating means comprising a yoke attached to the looper, an angularly 2. In a sewing machine having a work set driving crank, and universal joint con nection between said yoke and driving crank arranged to impart reciprocating movements across the path of the needle and a quarter turn between reciprocating movements.

3. In a sewing machine having a-work support, a presser foot and work feeding means, the combination of a reciprocating needle, and a looper operating above the work support and presser foot and cooperating with said needle, a floating frame having looper bearings and universal joint support adjacent to the path of the needle, and looper operating means adapted to cause said looper to move forwardly above the needle on one side of the line of stitches and backwardly below the needle'on the same side of the line of stitches, and to turn 90 at the ends of its forward and backward strokes. I

4. In a sewing machine having a work support, a presser foot andwork. feeding means, the combination of a reciprocating needle, and a looper movable forwardly and backwardly across the path of the needle,

with a floating frame having looper supporting bearing and universal joint support adjacent to the path-of the needle, causing the looper to operate on one side only of the line of stitches.

5. In a sewing machine having a work support, a presser foot and work feeding means,-the combination of a reciprocating needle, and a looper movable forwardly and backwardly across the path of the needle, with a floating frame formed with aligned looper bearings'and horizontal and vertical pivot supports at one end of said frame adjacent to the path of the needle and above said aligned bearings'l 6. In a sewing machine having a frame, a work support, a presser foot and work feeding means, the combination of a'recipro- Y eating needle, and a looper movable forwardly and backwardly above and below the path of the needle, with. a floating bearing frame formed with aligned looper bearings and a horizontal pivot hearing at one end of said frame above said aligned bearings, and 'a vertical pivot pin journaled in the machine frame and pivotally connected with said horizontal pivot bearing.

7. In a sewing'machine having a frame, a work support, a presser foot and'work feeding means, the combination of a stitch forming needle, and a looper reciprocating across the path of the needle, with a floating looper bearing frame, a vertical pivot pin having horizontal pivot connection with one end of said bearing frame, and a vertical bearing block adjustably mounted in the machine frame, said bearing block having an eccentric bearing opening in which said vertical pivot pin is journaled.

8. In a sewing machine having a frame, a work support, a presser foot and work feeding means, the combination of a stitch forming needle, and a looper reciprocating across the path of the needle, with a floating looperbearing frame formed at its forward end with a horizontal bearing yoke, a vertical pivot pin, a horizontal pivot pin connecting said yoke and said vertical pivot pin, a vertical bearing block adjustably mounted "in the machine frame and having an eccentric bearing opening in which said vertical pivot pin is journaled.

9. In asewing machine having a work support, a presser foot and work feeding means, the combination of a stitch forming needle, and a looper mounted upon a 100 er rod and movable forwardly and backwar y across the path of the needle, with a floating looper-bearing frame having universal joint support at its end adjacent to the path of the needle to cause the looper to operate on one side only of the line of stitches, and looper driving mechanism comprising a yoke secured tothe l'ooper rod, a bearing sleeve jointed to said yoke, and an angularly set driving crank upon which said sleeve is journaled.

CHARLES A. DEARBQRN. 

